In the active liquid crystal display device, each pixel has a thin film transistor (TFT) whose gate is connected to the horizontal scanning line, the drain is connected to the data line in the vertical direction, and the source is connected to the pixel electrode. Applying a sufficient voltage across the horizontal scan line will cause all the TFTs on that line to be turned on, the pixel electrode on the horizontal scanning line is connected with the data line in the vertical direction so as to write the display signal voltage on the data line into the pixel and control the light transmittance of the different liquid crystal so as to achieve the effect of controlling the color. Currently active LCD panel horizontal scan line driven mainly by the panel to complete the external IC, the external IC can control the level of the scan line at all levels of charge and discharge. The GOA technology can use the original LCD panel manufacturing process will be horizontal scan line driver circuit in the display area around the substrate, so that it can replace the external IC to complete the horizontal scan line driver. The GOA technology can reduce the bonding process of the external IC, have the opportunity to enhance productivity and reduce product cost, and can make the liquid crystal display panel is more suitable for the production of narrow border or borderless display products.
Conventional GOA gate driving circuits typically include a plurality of GOA driving units cascaded, with each stage of the GOA driving unit corresponding to driving a horizontal scan line. As shown in FIG. 1, the main structure of an existing GOA driving unit includes a pull-up control part 10, a pull-up part 20, a key pull-down part 30 and a pull-down holding part 40, and a capacitor boast CB responsible for potential uplift. Take the GOA circuit of 4 CK input signals as an example, for the nth-level GOA unit, the pull-up control part 10 is responsible for controlling the opening time of the pull-up part 20, generally according to the scan driving signal Gn−2 passed by the first two stages GOA driving unit, outputs the gate control signal Qn (commonly referred to as Q-point); the pull-up part 20 is controlled by the gate control signal Qn and is mainly responsible for outputting the clock signal CK as the scan driving signal Gn of the local level circuit; the key pull-down part 30 is responsible for pulling down the gate control signal Qn and the scanning driving signal Gn to the low level at the first time, i.e., when receiving the scan driving signal Gn+2 of the high level passed by the latter two stages GOA circuit unit, lowering the gate control signal Qn and scan driving signal Gn of the local level circuit to a low level turns off the sweep signal first; the pull-down holding part 40 is responsible for holding the gate control signal Qn and scan driving signal Gn of the local level circuit in the close state (i.e., low level potential); the C boast is responsible for the Q point of the second lift, so conducive to the output of the scan driving signal Gn of the pull-up part 20.
Splicing screen technology, refers to the larger size of the LCD screen is cut into smaller size display, and then a number of smaller size display spliced to obtain a specific size of the display. With the development of the splicing screen technology, when the larger size of the liquid crystal display screen, set at the edge of the LCD screen of the GOA gate driving circuit of the proposed series of arbitrary cutting requirements. However, as described above, the conventional GOA gate driving circuit is controlled by the scan driving signal Gn+2, which is transmitted from the GOA circuit unit of the latter two stages, for the GOA circuit unit of each stage, if an arbitrary cut is made, for example, cutting at the n-th stage, in which the n-th stage is the last-stage circuit cell, the signal Gn+2 is no longer provided after the completion of the cutting to control the n-th level key pull-down part 30, leading to the level GOA circuit unit does not work, and even lead to the complete failure of the GOA gate driving circuit. Therefore, the current liquid crystal display, in which the GOA gate driving circuit is unable to meet the requirements of cutting in any number of stages.